I've got three things. The last is the key in a "I know more now" sense but the first two provide the framework to let you go ahead and do it or hold you back.

Confidence. You are only as good as you let yourself be. Believe in yourself more. Don't let your worries block your development.

Forgiveness. Forgive yourself for mistakes and not knowing things. As that DHH viral Twitter thing showed, even the best and most productive developers Google the basics all the time

Challenges. I grew the most as a developer when I had to do something and I needed to get something done. Be it a side project, new job or saying yes to something a little out of your comfort zone, challenges help you forge ahead with purpose.

It's often why books and courses don't get you that further ahead on their own. It takes that need to fix x or implement y to really develop